CdS - ZnS quantum dots

The dependence of optical properties on particle size is the unique and most attractive feature of quantum dots. For example, by controlling the size of the particles, the emission wavelength of CdSe quantum dots is continuously adjustable in the entire visible light range. However, two-element quantum dots, such as CdSe quantum dots, have two disadvantages. First, its surface defects form a surface trap state, which reduces the luminous efficiency and stability. By encapsulating ZnS on the surface of quantum dots, forming a Core-shell structure can reduce surface defects, but the mismatch of CdSe and ZnS lattices greatly affects its luminous efficiency and optical stability. Second, the extinction coefficient of quantum dots is directly proportional to the volume of particles. The emission intensity of the material labeled with 6nm (red light) CdSe quantum dots is thirty times that of 2 nm (green light) quantum dots, which will cause a difference in detection sensitivity.
Different from the two-element quantum dots, the gradient alloy CdS/ZnS quantum dots developed by Muke Nano has added ternary alloy transition components in the luminescent core and ZnS shell, which brings the following advantages:
1. By adjusting the composition of alloy elements to control its optical performance, prepare quantum dots with the same volume but different luminescence frequencies, thereby reducing the difference in detection sensitivity caused by the application of different color quantum dots;
2. The alloy quantum dots have strong lattice strength and stable performance;
3. Realize the gradual transition of the crystal lattice, effectively reduce the internal pressure caused by the defects of the quantum dots lattice, so that the quantum dots have higher luminous efficiency and stability.

Sample information:

Sample luminous photo:

Transmission electron microscope photo:

Luminescence and absorption spectra:

Sample parameters: